lepu-test-platform-web/node_modules/css-select/lib/compile.js

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/*
compiles a selector to an executable function
*/
module.exports = compile;
module.exports.compileUnsafe = compileUnsafe;
module.exports.compileToken = compileToken;
var parse = require("css-what"),
DomUtils = require("domutils"),
isTag = DomUtils.isTag,
Rules = require("./general.js"),
sortRules = require("./sort.js"),
BaseFuncs = require("boolbase"),
trueFunc = BaseFuncs.trueFunc,
falseFunc = BaseFuncs.falseFunc,
procedure = require("./procedure.json");
function compile(selector, options, context){
var next = compileUnsafe(selector, options, context);
return wrap(next);
}
function wrap(next){
return function base(elem){
return isTag(elem) && next(elem);
};
}
function compileUnsafe(selector, options, context){
var token = parse(selector, options);
return compileToken(token, options, context);
}
function includesScopePseudo(t){
return t.type === "pseudo" && (
t.name === "scope" || (
Array.isArray(t.data) &&
t.data.some(function(data){
return data.some(includesScopePseudo);
})
)
);
}
var DESCENDANT_TOKEN = {type: "descendant"},
SCOPE_TOKEN = {type: "pseudo", name: "scope"},
PLACEHOLDER_ELEMENT = {},
getParent = DomUtils.getParent;
//CSS 4 Spec (Draft): 3.3.1. Absolutizing a Scope-relative Selector
//http://www.w3.org/TR/selectors4/#absolutizing
function absolutize(token, context){
//TODO better check if context is document
var hasContext = !!context && !!context.length && context.every(function(e){
return e === PLACEHOLDER_ELEMENT || !!getParent(e);
});
token.forEach(function(t){
if(t.length > 0 && isTraversal(t[0]) && t[0].type !== "descendant"){
//don't return in else branch
} else if(hasContext && !includesScopePseudo(t)){
t.unshift(DESCENDANT_TOKEN);
} else {
return;
}
t.unshift(SCOPE_TOKEN);
});
}
function compileToken(token, options, context){
token = token.filter(function(t){ return t.length > 0; });
token.forEach(sortRules);
var isArrayContext = Array.isArray(context);
context = (options && options.context) || context;
if(context && !isArrayContext) context = [context];
absolutize(token, context);
return token
.map(function(rules){ return compileRules(rules, options, context, isArrayContext); })
.reduce(reduceRules, falseFunc);
}
function isTraversal(t){
return procedure[t.type] < 0;
}
function compileRules(rules, options, context, isArrayContext){
var acceptSelf = (isArrayContext && rules[0].name === "scope" && rules[1].type === "descendant");
return rules.reduce(function(func, rule, index){
if(func === falseFunc) return func;
return Rules[rule.type](func, rule, options, context, acceptSelf && index === 1);
}, options && options.rootFunc || trueFunc);
}
function reduceRules(a, b){
if(b === falseFunc || a === trueFunc){
return a;
}
if(a === falseFunc || b === trueFunc){
return b;
}
return function combine(elem){
return a(elem) || b(elem);
};
}
//:not, :has and :matches have to compile selectors
//doing this in lib/pseudos.js would lead to circular dependencies,
//so we add them here
var Pseudos = require("./pseudos.js"),
filters = Pseudos.filters,
existsOne = DomUtils.existsOne,
isTag = DomUtils.isTag,
getChildren = DomUtils.getChildren;
function containsTraversal(t){
return t.some(isTraversal);
}
filters.not = function(next, token, options, context){
var opts = {
xmlMode: !!(options && options.xmlMode),
strict: !!(options && options.strict)
};
if(opts.strict){
if(token.length > 1 || token.some(containsTraversal)){
throw new SyntaxError("complex selectors in :not aren't allowed in strict mode");
}
}
var func = compileToken(token, opts, context);
if(func === falseFunc) return next;
if(func === trueFunc) return falseFunc;
return function(elem){
return !func(elem) && next(elem);
};
};
filters.has = function(next, token, options){
var opts = {
xmlMode: !!(options && options.xmlMode),
strict: !!(options && options.strict)
};
//FIXME: Uses an array as a pointer to the current element (side effects)
var context = token.some(containsTraversal) ? [PLACEHOLDER_ELEMENT] : null;
var func = compileToken(token, opts, context);
if(func === falseFunc) return falseFunc;
if(func === trueFunc) return function(elem){
return getChildren(elem).some(isTag) && next(elem);
};
func = wrap(func);
if(context){
return function has(elem){
return next(elem) && (
(context[0] = elem), existsOne(func, getChildren(elem))
);
};
}
return function has(elem){
return next(elem) && existsOne(func, getChildren(elem));
};
};
filters.matches = function(next, token, options, context){
var opts = {
xmlMode: !!(options && options.xmlMode),
strict: !!(options && options.strict),
rootFunc: next
};
return compileToken(token, opts, context);
};